Comparison of the conformation and stability of the native dimeric, monomelic, tetrameric and the desensitized forms of the nucleotide pyrophosphatase from mung bean (Phaseolus aureus) seedlings

A homogenous and crystalline form of nucleotide pyrophosphatase (EC 3.6.1.9) fromPhaseolus aureus (mung bean) seedlings was used for the study of the regulation of enzyme activity by adenine nucleotides. The native dimeric form of the enzyme had a helical content of about 65% which was reduced to almost zero values by the addition of AMP. In addition to this change in the helical content, AMP converted the native dimer to a tetramer. …